An installation, in particular a high-voltage or medium-voltage substation, is controlled by a distributed installation control system from field devices which are connected to one another via communications buses. FIG. 1 shows, schematically, a structure of an installation control system having field devices 1, a control station 2, a first and a second communications bus 3, 5 and a bus coupler 4. The field devices 1 control, regulate, monitor and protect primary units 6 in the installation which carry out the installation's actual purpose. Primary units 6 are, for example, switches, drives, generators or transformers. The bus coupler 4 connects communications buses 3, 5 which have different hardware and/or protocol characteristics, so that the communication buses 3, 4, 5 together form a communications network 3, 4, 5. The communications network 3, 4, 5 transmits messages for controlling the control station 2 to the field device 1 and messages from the field devices 1 to one another and to the control station 2 where, for example, they are displayed or stored. A field device 1 has at least one program element or one function for transmission of these messages associated with it in the control station 2. This function must be aware how communication with the field device 1 can be carried out. Conversely, the field device 1 must also be aware how messages can be transmitted to the associated function.
In any description of this communication, a distinction is drawn between                logic links, which describe transmitters, receivers and the nature of the message, and        communications parameters, which describe how the transmission takes place.        
Logic links are specified by unit identifications or network addresses. Communications parameters contain data types and data formats which are required when calling functions. Such information about a communications link is defined on an application layer in the generally known ISO communications layer model.
An individual message via a logic link between a field device 1 and an associated function conveys, for example, a position of a switch which is controlled by the field device 1, to an optical display within an installation diagram and/or to an event list and/or to an alarm function in the control station 2. A Standard for definition of communications links for station control engineering is described in a draft of an IEC Standard 61850. A summary of this can be found in the lecture documents relating to a VEW Energie AG Workshop of 1.21.99, by Jochen Haude.
During the configuration or engineering of an installation based on the prior art, device functions of the field device 1 and functions on a control station 2 are selected for integration of a field device 1, these functions are associated with one another, and logic links and communications parameters are specified. This is done by means of signal lists which specify in the form of text which functions of the control station 2 are associated with a specific message or a specific signal from a field device 1. Entries for the signal lists are produced in a first step by configuration tools for the individual field device 1, in which case field devices 1 generally have different configuration tools for protection functions and for control functions. In a second step, these entries are collected using an integration tool, and the signals are manually associated with one another. In a third step, specification data are produced for the individual field devices 1 and the control station 2 and indicate a receiver address, based on the association, for each signal and each message. The specification data produced are stored in files which are respectively associated with the field device 1 and the control station 2. During physical installation of a field device 1 and commissioning of the installation, these specification data are loaded in the field device 1 and in the control station 2. The appropriate communications links are thus produced, that is to say are ready for use.
Despite the use of special development tools, a large amount of manual effort is, however, required for specification of the links and interactions between functions during planning and commissioning. Furthermore, appropriate specialist knowledge is required in this case, so that, in addition to installation specialists, specialists in control engineering and communication are also required during planning and commissioning. Owing to the manual processes and the complexity of an installation, errors occur, which result in increased commissioning effort and faults during operation. Retrospective corrections to the installation are difficult to carry out and are risky.